DSLR Camera Construction
DSLR means "Digital Single Lens Reflex". These digital cameras take photographs using an image sensor that converts light to electronic signals. These cameras are equipped with mirrors that guide light from the lens into the viewfinder by reflecting it upward, hence the term “reflex.” The light that is reflected upward falls on the viewfinder focusing screen; after passing through the screen, it then proceeds through a pentaprism or pentamirror to the viewfinder eyepiece window. This allows the photographer to view the image from the camera lens directly in the viewfinder. When the shutter-release button is pressed all the way down, the mirror is raised and the light coming through the lens proceeds straight through to the shutter curtain. The curtain simultaneously opens to allow the light to fall on the image sensor and a photograph is taken. The shutter then closes and the mirror drops back into its original position.
Exposure Modes
Shooting modes fall into three categories: auto, scene, and P, S, A, and M modes. In auto and scene modes the camera controls shutter speed and aperture. P, S, A, and M modes are known as exposure modes and give photographers a choice as to which elements of exposure—aperture or shutter speed—they wish to control.
Mode P (Programmed Auto)
The camera automatically adjusts aperture and shutter speed for optimal exposure, but the photographer can choose from different combinations of aperture and shutter speed that will produce the same exposure. This is known as flexible program.
Mode S (Shutter-Priority Auto)
The photographer chooses the shutter speed and the camera automatically adjusts aperture for optimal exposure.
Mode A (Aperture-Priority Auto)
The photographer chooses the aperture and the camera automatically adjusts shutter speed for optimal exposure.
*Note: that in all three modes—P, S, and A—exposure is automatically adjusted for optimal results.
Mode M (Manual)
The photographer chooses both aperture and shutter speed, providing the greatest latitude for creative expression. Choosing the wrong combination could, however, result in photographs that are too bright (overexposed) or too dark (underexposed). It is recommended to use the camera exposure indicator as a guide when choosing aperture and shutter speed.
Flash Mode
Most DSLR Cameras are equipped with a built-in pop-up flash unit. If the camera is in auto mode, the flash will fire automatically when lighting is poor or the subject is back lit. The same is true in portrait, close-up, and other scene modes. In P, S, A, and M modes, the photographer can manually turn the flash on and off.
If a flash is not used when lighting is poor, shutter speeds will slow and photographs may be blurred. If the subject is back lit, details in shadow areas may be lost. The flash can be used to prevent blur or to illuminate details in backlit subjects.
Different flash modes are available to control the effect produced by the flash. These flash modes include fill flash, slow sync, and rear-curtain sync.
Fill Flash
Shutter speed is automatically set to around 1/60 s and the flash fires with each shot, brightening poorly lit portrait subjects. Because the intensity of the light from the flash diminishes with distance, objects behind the main subject will appear dark.
Slow Sync
The flash is used to light the main subject, and slow shutter speeds are used to ensure that objects in the background that are not fully lit by the flash are correctly exposed. Portrait subjects will be brightly lit and the shutter will remain open after the flash has fired to ensure that night scenery or dark interiors behind the portrait subject are correctly exposed.
Rear-Curtain Sync
In this mode, the timing of the flash differs from that in other modes. In other flash modes, the flash fires as the shutter opens, but in rear-curtain sync the flash fires just before the shutter closes. This ensures that light trails created by moving light sources appear to follow the moving object.
Flash Level (Guide Number)
In flash photography, the light from the flash is used to illuminate the subject. The distance at which a built-in flash can light a subject is however limited. The flash guide number (GN) is a measure of the distance at which the flash can illuminate a subject. The higher the guide number, the greater the distance at which the light from the flash is sufficient for optimal exposure.
The formula for calculating the guide number is: Guide number (GN)=distance (meters) × aperture (f-number).
Using the guide number, it is easy to calculate the how close the subject should be at a given aperture or the aperture required to photograph a subject at a given distance. If the flash unit has a guide number of 12 at ISO 100 and aperture is set to f/4, the subject can be up to 3 m away. If the subject is more than 3 m distant , the flash will not be bright enough to light the subject and the photograph will be underexposed. Increasing ISO sensitivity increases the guide number; consequently, raising ISO sensitivity makes it possible to achieve optimal exposure at greater distances. DSLR Cameras can also be used with optional flash units with higher guide numbers. Using an external flash unit makes it possible to achieve optimal exposure at greater distances than with the built-in flash.
*It is recommended to use external flash units when taking photographs at weddings and in other situations in which you may frequently be taking photographs at a distance from the subject.
Autofocus
Auto focus (AF) is the system that automatically adjusts camera focus.
Cameras typically have a two-stage shutter-release button: a first stage in which the shutter-release button is lightly pressed halfway, and a second in which the shutter-release button is pressed the rest of the way down. The camera focuses when the shutter-release button is pressed halfway and takes a picture when the button is pressed the rest of the way down.
Camera settings can be changed so that the camera can be focused manually by rotating the lens focus ring. This is known as manual focus (MF).
AF-Area Mode (Viewfinder)
The area of the frame that the camera will use for autofocus is shown by focus points in the viewfinder. Photographers can choose where the camera will focus by choosing a focus point. The selection can be made by the photographer or left up to the camera. The setting that determines how the focus point is selected is called AF-area mode. You can choose from auto-area AF, single-point AF, dynamic-area AF, and 3D-tracking. These AF-area modes are described below.
Single point: The photographer selects the focus point manually; the camera focuses on the subject in the selected focus point. Choose for stationary subjects.
Dynamic area: The photographer selects the focus point manually as above, but if the subject briefly leaves the selected focus point, the camera will focus based on information on the subject from surrounding focus points. Choose for subjects that are moving unpredictably.
Auto area: The camera detects the focus point containing the subject and focuses automatically.
3D tracking: The photographer selects the focus point manually; if the shutter-release button is kept pressed halfway after the camera has focused, the photographer can change the composition and the camera will automatically choose a new focus point as necessary to maintain focus on the selected subject.
AF-Area Mode (Live View)
In live view photography, the focus area for autofocus is shown in the monitor and can be positioned using the multi selector. AF-area mode controls how the focus area is selected. The AF-area modes available in live view include wide- and normal-area AF, subject-tracking AF, and face-priority AF. AF-area mode selection is also available during movie recording.
Focus Mode (Viewfinder)
Autofocus is performed when the shutter-release button is pressed halfway. The photographer can choose whether the camera locks or continues to adjust focus while the shutter-release button is pressed halfway. The setting that controls this behavior is focus mode.
Single-servo AF (AF-S)
In single-servo AF (AF-S), focus will lock if the shutter-release button is kept pressed halfway after the camera focuses.
Continuous-servo AF (AF-C)
In continuous-servo AF (AF-C), the camera will continue to focus if the shutter-release button is kept pressed halfway after the camera focuses. Because the camera continues to focus up to the moment the shutter-release button is pressed all the way down, this mode is a good choice for subjects that are in motion.
Autofocus - Auto
AF-A is where the camera selects and goes between the last two modes. If it thinks the subject you are photographing is stationary, then it will automatically use AF-S focus mode. If it picks up that the subject you’re photographing is a moving subject, then it will automatically use AF-C focus mode. This is also the default camera focus mode, unless you change the setting to AF-C or AF-S.
Focus Lock
Focus lock is used to change the composition without changing focus. If you frame the shot so that the main subject is in the selected focus point, focus, and then change the composition while keeping the shutter-release button pressed halfway to lock focus, you can create compositions in which the main subject is not in a focus point but is nevertheless in focus.
Manual Focus
Nowadays, there is usually an option to switch between auto and manual focus on the side of the actual lens. In other case, it is included as you come across a lens that doesn’t give you AF option.
Autofocus lock (AF Lock)
Autofocus lock: the act of fixing (locking) focus once it has been acquired by the camera; while focus is locked, the photographer can change the composition without changing focus. This is effective if the subject in question will not be in a focus point in the final composition.
What is Photography?
It is the art (or process) of capturing light usually with the film or digital sensor to create an image.
Fundementals Of Photography
No matter what photography means to you - a passion, a hobby or a profession, its a way to capture memories and tell stories, or simply a means to show off on social media— there are a multitude of benefits for mastering fundamentals of photography. The three most important pillars of photography are Shutter Speed, Aperture and ISO.
Shutter Speed: The amount of time your camera sensor is exposed to capture an image. It is responsible for two things: Changing the brightness of an image, and creating dramatic effects by either freezing action or blurring motion.
Aperture: It is basically a hole (aperture blades or diaphragm) in your camera’s lens that lets light pass through. It can add dimension to your photos by controlling depth of field. Widest aperture gives you a blurred background with a beautiful shallow focus effect. At the other, it will give you sharp image from the nearby foreground to the distant horizon. On top of that, it also alters the exposure of your images by making them brighter or darker.
How aperture affects exposure?
A large opening will allow a lot of light making your images brighter and creates foreground and background blur. This is often desirable for portraits, weddings, or any general subject you would want to isolate. While small aperture does the opposite. Makes your images dark and it results in smaller background blur. This is desirable for landscapes, architecture etc.
What are F-stops?
F-stops or F- numbers are a way of describing the size of aperture for a particular image. It is the ratio of the lens focal length to the diameter of the entrance pupil.
Large Aperture Vs Small Aperture: This is an important part of aperture that confuses beginners more than anything else. Small numbers (F/1.4, F/1.8, F/2, F/2.8 etc) represent large, whereas large numbers (F/8, F/9, F/10, F/11, etc) represent small apertures. This causes a huge amount of confusion among the most photographers, because it’s completely the reverse of what you would expect at first. However, as strange as it may sound, there is a reasonable and simple explanation that should make it much clearer to you - Aperture is a fraction.
When you are dealing with an f-stop of F/16, for example, you can think of it like the fraction of 1/16. Hopefully, you already know that a fraction like 1/16 is clearly much smaller than 1/4. For this exact reason, an aperture of f/16 is smaller than f/4.
ISO: It's another important pillars of photography and has major effect on your images. The acronym ISO stands for “International Standardization Organization”. However, camera ISO does not directly refer to the organization that creates various technology and product standards. In simple terms, it is a camera setting that will either brighten or darken your image. Every camera has common ISO values.
ISO 100 (low ISO)
ISO 200
ISO 400
ISO 800
ISO 1600
ISO 3200
ISO 6400
ISO 12800 (High ISO)
Quite simply, when you double your ISO, you are doubling the brightness of the image. So, a photo at ISO 800 will be twice brighter than ISO 400, which will be twice brighter than ISO 200.
(Note: Modern digital cameras have extended “HI” and “LO” ISO values that might stretch beyond their native range. However, these are completely simulated and lower your image quality. It is recommended avoid them).
White Balance: It is used to adjust colors to match the color of the light source so that white objects appear white. Subjects may be lit by a number of different light sources, including sunlight, incandescent bulbs, and fluorescent lighting. Although to the naked eye all these different light sources may appear colorless, in fact they emit light of different colors. The image sensor in a digital camera will reproduce these color differences just as they are, with the result that without additional processing the color of the photograph would appear to change according to the light source. Auto white balance automatically processes the image to remove unwanted color casts by, for example, making photographs taken under incandescent bulbs more blue to correct the reddish cast of this type of lighting. Normally, auto white balance will produce the desired results without the photographer having to worry about the type of lighting. If auto white balance does not produce the desired results, the photographer can choose from a number of fixed white balance options according to the weather or the light source. The photographer can also choose a setting for direct sunlight or incandescent lighting to introduce a deliberate red or blue cast according to their creative intent.
What are the elements of Photography?
Light: It’s the most important aspect of photography. The word photography is derived from the Greek words "photos" which means “light” and "graphe" which means “drawing” so the word literally means “drawing with light” or “painting with light”. Without it, most subject won’t make an interesting photo.
Line: A line is a one-dimensional representation of an object. Everything starts with a line, and lines can make up shapes, and shapes compose form, and form composes texture, and texture composes the pattern. It can be long, short, thick, and thin. They can also go horizontal, vertical, or diagonal. They can also be straight, curvy, jagged or broken. But most importantly, lines can also cause the viewer to do something.
(If you’re a beginner, it is important that you learn to see the world in terms of lines, shapes, forms, textures, and patterns).
Shape: Lines that converge with each other can form shapes. It represents objects in a two-dimensional plane, and they are used in photography to create a sense of space and substance. Shapes, whether they’re rectangular, round, etc., can be used in a lot of different ways.
Form: If you add a third dimension or thickness to a shape, it yields form. The form is what makes a photograph appear life-like. And while photography is mostly presented in a two-dimensional plane, there are certain techniques that photographers use in order to represent form by creating illusion or depth or thickness.
Texture: It represents the details that are on the surface of a subject. Like the form, it can be a challenge to capture texture or how an object feels in a two-dimensional plane, but it can also be achieved through the use of careful lighting.
Pattern: A pattern in art is defined in the dictionary as “a repeated form or design”. Indeed, when you create a repetition of shapes and textures, a pattern is formed.
Color: It helps to set the mood of the photo & can play significant role in touching the viewer on an emotional level.
Space: Another important element of photography that also gives an image a three-dimensional feeling. It gives depth to an image and suggests the distance between different objects and perspective. The “positive space” is the space taken by the subject and the “negative space” is the blank space taken by background and foreground.
Perspective: As a photographer, it is one of the habits that you need to break out of is shooting images from standing straight position. Shooting from different angles (either over the head or low level) gives your image different field of view and makes it look grander and dominant.
Composition: Also known as "Framing". It means arranging of elements or objects in a frame. Though there are many composition techniques but the best way to illustrate it is, the rule of thirds.
(A balanced composition doesn’t always mean putting your subject in the dead center of the frame to make the left and right sides of the frame symmetrical, it doesn’t work that way in photography.)
Depth of Field: It is the distance between the closest and farthest objects in an image to appear sharp.
Histogram: It is a graphical representation of the tonal values of your image. In other words, it shows the amount of tones of particular brightness found in your photograph ranging from black (0% brightness) to white (100% brightness). Most digital cameras allow you to see a live histogram even before you take the shot. The features may vary from camera to camera, refer your camera manual to find out how to display the histogram on your camera.
Metering
Metering is used to measure the brightness of the subject. The camera optimizes exposure by adjusting shutter speed, aperture (f-number), and ISO sensitivity according to the brightness of the subject, which is measured using the camera's built-in metering sensor. The camera does not simply measure the overall brightness of the frame, but measures brightness separately in multiple areas of the frame. The metering mode determines which areas of the frame are used by the camera to measure subject brightness and how the camera sets exposure. Normally the camera uses matrix metering, in which it divides a wide area of the frame into multiple segments and sets exposure based on a variety of information, including subject brightness and color. You can also choose center-weighted metering (in which the camera assigns the greatest weight to the center of the frame) and spot metering (in which the camera meters the area around the selected focus point).
Matrix Metering: Ensures a balance between light and dark areas.
Center-weighted Metering: Exposure is set correctly for the center of the frame.
Spot Metering: Exposure is set correctly for the portrait subject at the selected focus point.
Exposure Compensation
Exposure compensation is used to alter exposure from the value selected by the camera, making photographs brighter or darker. Exposure is a matter of personal preference, and an exposure brighter or darker than that selected by the camera may sometimes better reflect the photographer's intent. The feature used in such situations is called exposure compensation. DSLR Cameras allow you to check the results immediately, so you can take a photograph, display it in the monitor, and then raise exposure compensation for brighter results or lower exposure compensation for darker results and take another picture.
Exposure compensation will be displayed as: –1.0, –0.7, –0.3, 0.0, +0.3, +0.7, +1.0, where “–1.0” is one step darker than the optimal exposure value selected by the camera.
Back Button Focusing
On most cameras on the back of the camera, on the side in which the shutter release button is, you’ll most likely find a button called AF-ON.
The AF-ON button is our back button focus.
Back button focus is when we reassign the autofocus function from the shutter button (which is usually the default) and assign it to the AF-ON button on the back of the camera. This means that instead of using the shutter release button to autofocus your shots, you will now use the AF-ON on the back of the camera. Usually, the workflow is that you will have your index finger on the shutter release button to take the capture, and your thumb on the AF-ON button to autofocus just before you’re about to take the shot.
Why Use Back Button Focus?
There are a number of reasons that you would use back button focus, but the main reason is to
Make focusing independent of the shutter release for control.
You want control over when the camera focuses and when the camera does not focus. That’s why we use back button focus. It’s about control. Control over when the camera focuses and when the camera doesn’t focus.
Because lists are so much easier to read let’s get a list of reasons why back button focus rocks!
- Having the focus independent of the shutter release for control.
- Making each button responsible for ONE FUNCTION, either capture or autofocus.
- Having independent functions prevents having to constantly refocus.
- Or the worst yet, mistakenly focusing instead of capture.
- You don’t have to switch between AF-C (Nikon) AI Servo AF (Canon) and AF-S (Nikon) One-Shot AF (Canon). You can keep your camera on AF-C but use it like AF-S by not using AF-ON to refocus.
- You don’t have to turn off autofocus if you want to use manual focus. Simply manually adjust the lens instead and the shutter release won’t refocus.
If we think about photography and the plane of focus/DoF, getting precise focus is crucial in getting an in-focus shot. By using the shutter release button as the autofocus, you risk not having as much control over where the camera focuses. Now you can turn off autofocus and use manual focus, but with back button focus you don’t have to.
Movie
Movie Options
The Movie settings option in the shooting menu controls movie quality, expressed as a combination of frame size, frame rate, and image quality (bit rate). Choose an option according to the scene and how the movie will be used.
Frame Size
“Frame size” refers to the horizontal and vertical dimensions of each frame, in pixels. The options available include 1920 × 1080, 1280 × 720, and 640 × 424; the larger the size, the higher the resolution of the movie when viewed on a TV, and the larger the image when displayed on a computer monitor. Note, however, that larger frame sizes produce larger files, reducing the footage that can be recorded to the memory card.
Movies recorded at frame sizes of 1920 × 1080 (Full HD) and 1280 × 720 (HD) have an aspect ratio of 16 : 9, while movies recorded at a frame size of 640 × 424 have an aspect ratio of 3 : 2.
Frame Rate
The “frame rate” is the number of frames recorded per second (fps). The higher the frame rate, the smoother the resulting movie. Supported frame rates include 60, 50, 30, 25, and 24 fps; at 60 fps, 60 frames are recorded every second.
Note: Some cameras offer frame rates of 60, 30, and 24 fps when NTSC (the video standard in use in North America, the Caribbean, and the Philippines) is selected for Video mode in the setup menu and rates of 50, 25, and 24 when PAL (the video standard in use in much of the rest of the English-speaking world) is selected.
The movies shown in cinemas have a frame rate of 24 fps, which makes this setting a good choice for re-cording footage with something of the feel of a theatrical release.
Movie Quality
Movie quality is a measure of the amount of compression used when recording movies. Nikon cameras offer a choice of “high” and “normal” quality. “High” quality movies are less compressed and higher quality and occupy correspondingly more memory, while “normal” quality movies are recorded at a bit rate that offers a balance between quality and file size. Choose “high” when quality is your first priority.
High Quality Videos - Quality will be high, compression will be low and file size will be very large.
Normal Quality Videos - Quality will be normal, compression will be high and file size will be small.
*Note: The “bit rate” is the amount of compressed data per second.
